The invention relates to a clamping unit.
Such clamping units are generally used for the stationary clamping of workpieces in drilling and milling machines as well as in machining centres, and also for actuating chucks for workpieces in rotary machining processes on lathes, grinding and indexing machines.
Clamping units of the type mentioned typically have hydraulic drive units for generating the clamping forces required for clamping or releasing workpieces. Such hydraulic units have, however, in addition to their high level of engineering effort, the disadvantage that these units respond relatively slowly to switching signals so that there is a problem with applications in which, for example, for reasons of productivity, very fast and precise clamping system motions are required for performing clamping processes or releasing processes.
From DE 20 2013 101 345 U1, a magnetic clamping device is known which has a clamping surface, at least one electromagnetic means of clamping for clamping a workpiece on the clamping surface, and a centering device for centering the workpiece, wherein the centering device has at least one primary clamping jaw that is slidable within the clamping surface. Associated with the primary clamping jaw is a clamping jaw that is movable into a lowered or raised position relative to the clamping surface. The clamping jaw has a separate drive, in particular, a pneumatic, hydraulic, mechanical, magnetic, in particular an electromagnetic, electromotive or manual lift drive. The use of electromotive drives is mentioned there only summarily.